definitly find a more powerful amp or a less powerful sub... actually even if you dont get the sub get a more powerful amp. if your asking will the two function together, then yes it will probably work to some degree, but the amp will need to pull soo much power from the car to power the sub i wouldnt bother with it. other than draining power from your car you will likely overheat the sub or amp. always try and keep the RMS rating of the sub and amp as close as possible to each other

i wouldnt. they always do that with package deals, throw underpowered amps in with decent subs. the RMS rating is usually half of the peak output rating, so a sub with a 1200W peak would be about 600W RMS(constant power). so a 600W RMS amp would be perfect, but getting anywhere close is good.

it all depends on what your looking for though. if you just want some bump, a package deal from best buy or circuit city will do the trick, especially if they will hook up the install for free, however i would stay away from online package deals. the best way to go is definitly piecing the system together yourself.

how much are you selling the 720 watt for?
cuz i got a alpine deck, infiniti 5x7's in the front and
dual 6x9's in the back which is fine but i need an amp
cuz i jus got a box and 2 12 inch subs it needs some kick ya
know. so how much is that amp?